1. Field of the Invention
The invention relates to a road information acquisition device and a road information acquisition method for obtaining road information such as a road elevation and a road gradient on a travel route of a vehicle.
2. Description of the Related Art
As described in Japanese Patent Application Publication No. 2004-37141 (JP-A-2004-37141), for example, a device for obtaining road information includes: road information storing means for storing the latitude/longitude of a plurality of points on a road; surface elevation storing means for storing surface elevation information relating to a plurality of points on a map; interpolated elevation value calculating means for calculating a road elevation value of the plurality of points on the road using the surface elevation data relating to the plurality of points on the map; and accuracy calculating means for calculating an accuracy of the calculated road elevation value from the road information or the surface elevation value information. By estimating the road elevation using this road information acquisition device, vehicle travel control enabling a reduction in fuel consumption, taking into account the road elevation and road gradient of the travel route, is performed.